The present invention relates to the field of gas turbine engines, particularly multi-flow turbojet engines, and relates to a system able to detect breakage of a machine shaft so as to shut down the machine in the shortest possible space of time.
In a multi-spool multi-flow turbofan jet engine, the fan is driven by the low-pressure turbine. When the shaft connecting the fan rotor to the turbine rotor breaks, the mechanical load on the turbine is suddenly removed whereas the engine gas flow continues to transmit its energy to the rotor. This then results in a rapid increase in the rotational speed of the rotor which is liable to reach its yield stress and to explode with the ensuing catastrophic consequences.